The 50 Heaviest Songs Before Black Sabbath: #20-11

The origin of heavy metal is a very fuzzy thing, but most historians and fans can agree that Black Sabbath’s eponymous 1970 debut was the first true metal album. Its thunderous drums, sinister riffs and downright evil lyrics left little to be debated, but what we at Guitar World wanted to know was this: What was the heaviest song before Black Sabbath?

We ranked these songs based on a variety of factors: distortion/fuzz, speed, darkness, volume and shock value. Most importantly, however, the song had to have been released before 1970. It would have been easy to list the first two Led Zeppelin and Jimi Hendrix albums and call it a day, but we dug deep to find some hidden heavy gems from the era of peace and love.

We'll be revealing 10 songs each day until Sunday, when we reveal the heaviest song before Black Sabbath.

20 - Led Zeppelin, "Communication Breakdown" (1969)
One of the first and finest examples of a chugging riff incorporating the low E string, and in many ways the blueprint for the New Wave of British Heavy Metal and, later, thrash. While nothing to write home about, Iron Maiden’s cover of this song is worth checking out.